The Molecular Cytology Core Facility (MCCF) at MSKCC assists in accelerating the research process by providing investigators with consultation, training and technical assistance in the execution of technologies for detection and analysis of molecules within their natural environment. The MCCF also adopts and modifies new technologies as appropriate to expand and enhance the research capabilities. Technologies applied in the MCCF include characterization of gene expression in situ (localization of mRNA and protein expression); in situ analysis of cell proliferation and cell death; histological evaluation and molecular in situ characterization of knock- out and transgenic mice with particular emphasis on analysis of embryonic phenotypes, mouse models of human tumors and human tumor samples. Two sequential steps are involved: 1. Tissue processing and execution of in situ molecular detection techniques 2. Application of a wide range of optical microscopy techniques in conjunction with digital imaging, image processing and image analysis to evaluate and present resulting data.